Gas burner unit



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GAS BURNER UNIT I O' lN-VENTOR M Y @2f/Mr dwf f fm ATTO R N EYS Nov. 26, 1940. c. o. NoRDr-:NssoN 2.222,822

GAS BURNER UNIT Filed June 4, 1937 2 SheeliS-Sheell 2 /45 /2 INVENTQR n jx MVM @M @im ffm,

ATTORNEYS Patented Nov. 26,1940 l l UNITED vSTATES PATENT OFFICE GAS BURNER UNIT Carl 0. Nordensson, Bualo, N. Y., assigner to llliberts-Gordon Appliance Corporation, Buff o, N. Y.

Application June 4, 1937, Serial No. 146,382 4 Claims. (Cl. 158-99) This invention relates to gas burners of the Another object of the invention is to provide type suitable for furnaces and low pressure heatan improved gas burner unit which will have v in'g boilers as well as for all kinds of industrial maximum flexibility of capacity without lowerheaters and high pressure boilers including heating its combustion efficiency, which will operate 5 ing and power boilers, stills, driers and kilns of eiciently on either low, medium or high gas 5 all types, annealing, baking and core ovens,lead l pressures, and which will burn all of the gases and gypsum pots, potato chip tanks, etc. in commercial use even including blast furnace The primary function of a gas burner is to and producer gases. mix gas and air, and generally the merit of the A further object of the invention is to progas burner may be indicated to some extent by -vide an improved gas burner unit which will be 10 the thoroughness of the mixing of the air and practically free from backflash and pulsation, combustible gas. This is particularly true inwhichk may be used effectively in combination burners employing all primary air, and the preswith oil burning equipment with quick change ent invention is particularly adapted for use in over from one fuel to the other lwithout any mixing the combustible gas yand primary air. change in the furnace or disturbance of the 15 Thorough mixing of the combustible gas and air burner setting, which is easy to install and opbefore ignition takes place results in quick and crate, which is relatively light, yet strong and complete combustion near the end of the burner ruggedl in construction, with which a pilot light with a, short flame and, requires a, minimum may be supplied as a part of the burner assemamount of excess air. Excess air reduces the bly, and Which Will be relatively inexpensive.

temperature produced by the combustion, yet Another object of the invention is to provide some excess air is necessary in order to insure an improved gas burner unit having a sensitive, complete combustion of all the gas.Y A thorough easily Operated lall Control which is suitable for and complete mixing of the gas and air m'ust be automatic as well as hand regulation, with which obtained if the amount of excess air is t0 be the amount Of all' admitted fOr mlXtllIe With the 25 reduced to aminimum. With thorough and rapid .combustible gas may be easily regulated and combustion of the gas with a minimum of excess equally distributed with reasonable accuracy of air, the result is a higher furnace temperature control'of the amllnt 0f all', and With Which and greater heat transfer from the combustion the air admitted is given somewhat of a whirling gases to the heating surfaces, and therefore the turbulence. 30V

stack mss is materially reduced with consequent- Another object of the invention is to provide 1y higher efficiency in the heating device. The an improved 88S burner unit which will be relareduction of the excess air to a minimum also tively Compact, easily instel-led in masonry Walls, reduces the oxidation of the heating surfaces and and ally Dumber assembled in Coupled relatiOn of the flu-nace lining, with resuting minimum for insertion as a single element in a furnace 35 upkeep expense for the heating devicewall, which will provide for thorough mixing of one object of the invention is to generally the combustible gas and air and maximum preimprove and simplify gas burner umts' and pap heating of the gas and air mixture before igniticularly muse utilizing an primary air in which tion, and with which the manifold may be easily l removed from the unit at the outside of the 40 Substantially au of the an' necessary for com' heating device for inspection, adjustment or 40 bustion is mixed with the gas before ignition change of the gas jets, without disturbing the takes P1aeburner setting in the wall of the heating device. AIlOlhel'- Oblecl" 0f the invention 1S t0 Provlde Other objects and advantages will be apparent a gas burner unit in which all the elf required from the following description of an embodiment 45 for combustion iS mixed with the ges befOre igniof the invention, and the novel features will be tion. With Wheh eOmplete. early end lepid mlX- particularly pointed out hereinafter in connecing of the combustible gas and aix is obtained, tion with the appended claims.

with which maximum furnace temperatures may In the accompanying drawings:

beobtained from agiven quantity of combustible Fig. 1 is a longitudinal sectional elevation 50' gas, with which maximum heat transfer from the through a gas burner unit constructed in accordcombustion gases to the heating surface may be ance with this invention and designed primarily obtained, and with which oxidation of the furfor use as an industrial burner; nace lining and heating surfaces is reduced to a Fig. 2 is an end elevation of the same as viewed minimum. -Y from the left in Fig. 1; 55

Fig. 3 is a transverse sectional elevation through the same, the section being taken approximately along the line 3-3 of Fig. 1;

Fig. 4 is a transverse sectional elevation through another portion of the same, the section being taken approximately along the line 4 4 of Fig. 1;

Fig. 5 is a sectional plan through a portion of the burner manifold andone of the discharge jets, the section being taken approximately along the line 5 5 of Fig. l;

Fig. 6 is a view similar to Fig. 5 except that that discharge jet is not in section and has been rotated angularly somewhat about its connection to the manifold in order to change the direction Vof discharge of the gases therefrom;

Fig. 7 is a transverse sectional elevation through another part of the unit, the section'being taken approximately along the line 1 1 of Fig. 1;

Fig. 8 is a sectional elevation through still another portion of the unit, the section being taken approximately along the line 8 8 of Fig. 1;

` Fig. 9 is a sectional plan of a portion of the same, the section being taken approximately along the line 3 9 of Fig. '1;

Fig. 10 is a perspective of one of the sections of the refractory lining;

Fig. 11 is a front face elevation of an industrial heater having in proper position in a wall therein a battery of four burner units that are constructed in accordance with this invention; and

Fig. 12 is a sectional elevation through the same, the, section being taken approximately along the line I2 I2 of Fig. 11.

In the illustrated embodiment of the invention, the improved gas burner unit includes a rectangular burner frame or casing I0, which may be of cast metal such as cast iron or steel, and this burner casing or frame is provided with an opening or passage I I therethrough from face to face which is circular at one zone of its length. A rectangular mixing casing I2 which is open at both ends is telescoped over a reduced end flange on the burner frame I0 and is secured against removal therefrom in any suitable manner such as by screws I3. A gas distributing manifold I4 is disposed within the opening or passage II of the burner'- casing I0, and preferably is spaced somewhat fromthe wall of the passage Il to provide for the passage of air' past the manifold at the exterior of its periphery. This manifold I4 is preferably a closed loop and circular, but it may of course be made of sections or of other shapes if desired. As shown, it is made of a single casting and is provided with radial ears or lugs I5, Figs. 7 to 9, which abut against that end face of the burner casing which is opposite from the casing I2, the lugs I5 being removably secured to the burner frame in any suitable manner, such as by screws I6. Y

A cylindrical casing I1 is open at both ends and at one endabuts against the end face of the burner frame III at the face opposite from the casing I2, 1and preferably the casing I1 telescopes over flanges I8 on the end face of the burner casing I0 and also over lugs or ears I9 extendingl endwise from the distributing manifold I4, Figs. '1 and 9. The casing I1 may be secured in position in any suitable manner such as by screws 20 which .pass through the casing I1 into the lugs or ears I9. Thus the casing I1 will be secured to the manifold I4 and through the latter will be detachably secured to the burner casing I0, and when the screws I6 are removed, the casing I1 and the manifold I4 may be removed -together as a unit. It win be noted that the screws I6, by which the casing I1 and the manifold I4 are attached to the end face of the burner casing I0, are outside of the casing I1 so as to be easily accessible when removal of the manifold I4 and casing I1 from the rest of the unit is desired.

A gas supply pipe 2l is coupled at one end, such as by a coupling 22, to'the manifold I4 and is then curved or bent into a central portion of4 the passage through the casing I1 and then extends outwardly through the open or outer end of the casing I1, as shown in Fig. 1. A valve, shutter or closure 23 is provided upon this outwardly projecting end of the pipe 2|"for adjustment therealong, and includes a sleeve 24, which slides freely on the pipe 2|, and a disk or plate 25 through which the sleeve 24 passes and which is secured against a flange 26V on the sleeve 24 intermediate the endsv of the latter. The valve 23 is preferably cup shaped or drum shaped and has a cylindrical wall 21 extending from the disc or end wall 25 and telescoping with the outer end of the casing I1. drum portion 21 telescopes loosely within the open end of the casing I1, and at its inner end is provided with an outwardly drawn peripheral bead 28 which by engagement with the inner wall of the casing I1 tends to steady the valve 23 in its telescoping adjustments along the casing I1, and at the same time stiiens the wall in which it is formed and also prevents'the passage of any large quantity of air between the inner wall of the casing I1 and the cylindrical drum or wall 21 of the closure.

One of the telescoping walls of the valve or shutter and the casing I1 is provided with slots or slot-like apertures which progress generally in a direction endwise ofthe casing I1 and preferably also with a circumferential component so that the slots actually extend in a direction both endwise ofthe casing I1 and also somewhat in a circumferential direction, as shown clearly in Fig. 1. Preferably these slots are provided in the cylindrical wall or drum section 21 and are designated by the reference character 29, because in the illustrated embodiment of the invention the drum portion 21 telescopes within the casing I1. Thus, as the valve or closure 23 is shifted endwise along the pipe 2| or is adjusted telescopically with respect to the casing I1, varying portions of the slots 29 will be uncovered for the entrance of air into the conduit formed of the casings III, I2 and I1, providing a very sensitive control for the air throughout approximately the full range of adjustment of the shutter. The oblique positions of the slots 29, that is, the' location of the slots so that they progress with components circumferentially and also endwise, appear to'improve the uniformity, thoroughness or completeness of the mixture of the gas and air within the conduit formed of the casing sections I0, I2 and I1, and this is believed to be due to the tendency of the oblique slots 29 to impart somewhat of a whirling turbulence to the air upon its entrance to the casing I1.

This whirling turbulence may be further increased by selection of the direction in which the streams of combustible gas are discharged into the air current, as will be explained presently. While the Valve or shutter 23 may be adjusted automatically in order to regulate the amount of air admitted, such automatic regulation has been omitted from the illustrated embodiment of the invention in the interest of simplicity and Preferably the cylindrical clearness, and a simple, manual device such as a set screw is illustrated for the purpose of securing the valve 23 in a desired position. Usually in industrial furnace.- heater and boiler installations, a battery of these burner units is employed, and therefore the number of burner units ignited or in use may be varied when a change in the heating eiiect is desired.

The gas distributing manifold I4-has a distributing passage 3l which, as shown, progresses in a direction around the interior of the burner frame such as in the form of a closed loop, and the center line of the passage 3l is approximately in a plane which is crosswise of the longitudinal axis of the conduit formed of the casing sections II), I2 and I'l. A plurality of gas discharge jets 32 and 33 are provided on the manifold I4, and discharge small streams of gas into the conduit generally in the direction-of air ow and these small streams have somewhat of an injector action to induce air flow along the conduit. The maximum possible volume of air passing through the conduit is governed, not only by the4 draft in the furnace or heater, but also by the pressure at which the combustible gas is discharged into the conduit, because the induction effect of the gas streams on the air iiow depends upon the velocity of discharge of such gas streams into the air in the conduit. The jets 32 are arranged -at intervals along the m-anifold I4 on one side of lthe plane through the center line of the passage 3l, and these jets leave the manifold at an acute angle to the plane of the center line of the passage 3I but after leaving the manifold I4 they are bent arcuately so as to discharge the small streams of combustible gas along the air passage through the conduit formed of casing sections IU, I2 and Il, in the direction of air ow as shown in Fig. 1.

The discharge jets 33 are arranged also along the manifold -I4 but on the side of the plane of the passage 3l opposite from the jets 32, and the jets 33 also in leaving the manifold project outwardly away from the plane through the center line of the passage 3| but at an acute angle thereto. After leaving the manifold, the jets 33 are curved arcuately so as to discharge small streams of combustible gas als'o along the conduit formed of sections III, I2 and 4I'I in the direction of air ow. The jets 33 are preferablystaggered with respect to the jets 32 in the passage, so as to obtain a more uniform distribution oi the gas in different parts of the air stream passing along the conduit. This staggered arrangement is shown particularly in Fig. 2. It will also be noted that the jets 33 extend radially further into the passage through the loop formed by the manifold I4 than do the jets 32.

The jets 32 and 33 at their free ends are also preferably provided with detachable nozzles or spuds 34 for determining the character .and size of the stream of gas which is discharged. The jets 32 and 33 `are prefer-ably threaded into holes provided in the manifold I4, and thus may be angularly adjusted on -the manifold by partial rotationin a threading direction so that the gas streams discharged by the jets may be in direction-s somewhat angularly, obliquely or tangentially to the direction of air ow through the conduit. -Such an adjustment of one of the conduits 33 from the position shown in Figs. 2-and 5 is shown particularly in Fig. 6, and an example of such an adjustment of -all of the jets 32 and 33 is shown in Fig. 8. If the jets are adjusted so that they have somewhat tangential or oblique angles with the centerline of the conduit, as shown in Fig. 8, the discharged streams will not only draw air through the conduit but will-impart a spiraling or spiral whirling of the air and gas streams in the conduit, with resulting greater length of .travel of the gases and air in the conduit and a more rapid, thorough and complete mixture of the combustible gases and air. The degree of such turbulence and whirling may of course be varied byappropriate angular adjustment of the jets in the manifold I4 so as to Vary the lateral deflection of the streams of combustible gas, but preferably all the jets have the same `angular positions with respect to the axis of the conduit.

The casing I2 is provided with a refractory lining 35 which may be made of any suitable refractory material, but preferably of a lightv refractory material which will withstand av temperature vof at least 2400 F. The lining is preferably divided longitudinally into a plurality of sections formed separately in order to reduce the tendency for the liningto crack and for ease of manufacture, and has a length which is sufficient to effect -thorough mixing of the gas and air and obtain a maximum preheat of the mixture before ignition thereof. The refractory sectionsl are preferably securely cemented together at their joints and into the casing I2 with' a suitable refractory cement. s One of these refractory lining sections is shown in perspective in Fig. 10, from which it will be noted that the lining is provided with a central cylindrical portion 36 projecting from an end face of a rectangular flange or head 31. l i

The flange or head 31 may be provided with apertures 38 at each of the corners, which apertures increase the lightness ci the lining and reduce its tendency to crack, `and one of these apertures 3 8 may be utilized for the passage of a pilot supply pipe -39, Figs. 2, 7 and 8. The other passages 38 may be closed, such as at an end thereof, if desired by any suitable refractoryplugs 40, Fig. 2. The lining 35 may conveniently extend somewhat beyond the open end of the casing I2 so as to form a continuation thereof, and the inner end face of the lining is preferably bevelled inwardly as at 4I so as to form a converging or constricting passage section immediately in front of and spaced somewhat from the manifold I4, so that any -air passing between the manifold I4 and the burner casing Ill will be de'- iiected by the bevelled portion 4I towardv the center of the conduit for mixture with the streams of combustible gas and air. 'I'he bevelled constriction also tends to create turbulence in the air stream.

The rectangular casing I2 may be formed in any suitable manner, but preferably'it comprises four plates of sheet metal assembled to form a rectangular body, and the abutting edges of the. plates at the corners are connected to angle bars 42 such as by rivets or screws. The angle `bars reinforce the casing at the corners. The sheet metal plates of which the casing I2 is formed may also carry angle bars 43 on their inner faces sembled in the burner opening in a wall of the combustion chamber with cement applied between the umts and the wall of the opening 44 so as to tightly seal the same. Inasmuch as the pilot supply pipe 39 passes through the refractory lining within the casing I2, and through an aperture in one of the corners of the burner casing I0, the pilot burner pipe will not interfere with the assembling of these various units in a furnace wall. The pipes 2I for supplying combustible gas to the different units may be connected to common headers 46 controlled by valves 41. If the burner unit is to be employed for low pressure heating boilers and for furnaces having automatic controls, each burner unit may, at its outer or air entrance end, be enclosed in -an auxiliary air box with a damper automatically controlled in a manner now common in various types of burners, to cut off the supply of air into the burner unit when the fuel is shut off. The damper of such an enclosure would operate independently of the valve 23 which regulates the quantity of air admitted during operation of the unit.

The operation of the burner unit appears to be clear from the foregoing description, but will be briefly summarized. The pilot light being lighted at all times, receives its supply of gas through the pipe 39 and this pilot, as observed in Fig. 2, is disposed somewhat across the stream of air leaving the conduit of the unit at the outer end of the refractory lining. A combustible gas is supplied through the pipe 2I to the manifold I4, and this gas is distributed through 'the passage 3I in the manifold to the various discharge jets 32 and 33. 'I'hese jets discharge a large number of small streams of the combustible gas into different portions of the conduit passage in the direction of air travel along the conduit, and these streams of gas, by somewhat of an injector action, aid the flow of airalong with the gas into the furnace combustion chamber through the refractory lining of the casing I2.

'Ihe quantity of air admitted is regulated by the valve or shutter or closure 23, which is adjusted telescopically along the pipe 2| until but little more than the necessary amount of air is included -to obtain complete combustion `when the burner is operated at desired or normal capacity under normal gas pressure. The air entering through the oblique slots 29 will be given somewhat of a turbulence in the conduit, and thus an evener distribution through the conduit and around all of the jets, and this turbulence may be increased or varied when desired by adjusting the angular positions of the jets 32 and 33, such as into the positions shown in Fig. 8 for example. I have found that adjustment of the jets into the positions shown in Fig. 2 to discharge streams of gas in directions approximately parallel to the longitudinal axis of the conduit is frequently advantageous when the gas delivered to the manifold I4 is under a relatively high pressure such as of approximately The combustible mixture will be ignited as it leaves the refractory lining.

The heat from the combustion chamber, into which the combustible and burning mixture is discharged, will heat the refractory lining of the conduit, which will in turn radiate some of this heat to th'e ingoing gas and air mixture and thus preheat it before admission to the combustion chamber of the furnace or heater, thus'ob- ,taining a rapid combustion of the gases when once ignited. The casing I2 and the refractory lining therefore are made of such length that a thorough mixing of the gas and air, and a maximum desired preheating of the mixture, are obtained before discharge into the heater. Thus each burner unit'is simple and sturdy, yet of light weight, and of flexible capacity. When one desires to inspect any burner, or to adjust the angular positions ofl the jets 32 and 33 such as in order to vary the turbulence set up in the air current by the discharged combustible gas, it is merely necessary to remove the screws I6 and, then remove the pipe 2|, the casing II and the manifold I4 as a unit, leaving the burner casing I0, the casing I2 and the lining 35 in position in the furnace wall. They may be replaced by reverse steps. Experience has demonstrated that a burner unit of this type is practically free from backflash and pulsation, and careful tests have indicated that remarkable efficiency is obtained.

With a burner unit of this type, one may obtain fora given furnace draft, the combustion of more gas per square inch of throat area when higher gas pressures are used than with low pressures, and the apertures of the burner spuds may be changed if necessary to vary the quantity of combustible gas delivered. With each change in the quantity of gas delivered by the spuds, whether by variations in the orices of the spuds or by regulation of the quantity or pressure of gas delivered to the manifold, the air valve 23 should be regulated accordingly to deliver the proper proportion of air necessary for complete combustion, and with a minimum of excess air. Burner units of this type have a relatively large range of capacities, such as, for example, from approximately 250 cubic feet per hour at a gas pressure of approximately 2 inches W. G. to 4000 cubic feet per hour at a`gas pressure of approximately 2 pounds per square inch, with substantially equal combustion efficiency throughout the range.

The rectangular shape lof the burner frame and of the mixing casing is advantageous for the reason that the rectangular shapes of this type are more easily fitted into masonry walls and fitted to one another in batteries, as will be observed from Figs. 11 and 12.

It will be understood that various changes in the details, materials and arrangements of parts, which have been herein describedand illustrated in order to explain the nature of the invention, may be made by those skilled in the art -within the principle and scope of the invention,

as expressed in the appended claims.

I claim as my invention:

1. A gas burning unit comprising a tubular conduit having an air entrance opening at one end and a refractory lining within the opposite end thereof and extending inwardly along the conduit for a substantial distance, means for discharging a gaseous fuel into the conduit at a point intermediate the ends of said conduit, said refractory lining having a head which fits the exit end of said conduitsaid lining between its inner end and said head being approximately cylindrical and largely spaced somewhat from the conduit wall, to reduce the .tendency for the lining to crack, said head having an aperture from face to face at one side of said cylindrical portion, a pilot burner disposed somewhat across the outlet end of said lining, and a pipe supplying fuel to said pilot burner passing endwise through said lining in said aperture whereby said conduit may be tightly set in the wall of the heater and said pilot burner will be within the portion of that conduit that is mounted in the heater wall.

2;. In a gas burner unit 0! the type having a tubular mixing conduit with an air entrance at one end, the combination therewith of an air regulating. tubular closure telescoping withthe air entrance end of said conduit and adjustable in a direction endwise thereof, and having its inner end open and at its outer end substantially closed, one of the telescoping walls of said closure and said conduit having slots arranged at intervals around its periphery and each progressing generally in a direction endwise thereof to vary the amount of air admitted to said conduit as said closure is adjusted in a direction endwise of said conduit.

3. In a gas burner unit of the type having a tubular mixing conduit with an air entrance at one end, the combination therewith of an air regulating, tubular closure telescoping with the air entrance end of said conduit and adjustable in a .direction endwise thereof, and having its inner end open and at its outer end substantially closed, one of the telescoping walls of said closure and said conduit having slots arranged at intervals around its periphery and each progressing generally in a direction endwise and also peripherally thereof so as to have direction components progressing both endwise and peripherally of the shell to vary the amount of air admitted to said conduit as said closure is adjusted in a direction endwise of said conduit.

4. In a gas burning unit, a rectangular frame having a discharge extension at one end thereof, and an inwardly extendingflange that provides a central restricted passage running lengthwise of the frame, a gas manifold frame abutting against said ange at the face of the flange oppo' site from said discharge extension and extending into said restricted passage, a tubular air supply shell telescoping with said manifold frame so as to extend therefrom in the direction opposite from said discharge extension, for conducting air to said restricted passage, means disposed outside of the passage formedby said air inlet shell for coupling said manifold frame to said flange and accessible for coupling and uncoupling at the end of said rectangular frame from which the air supply shell extends, said manifold having means for discharging gas into said restricted passage through said frame, whereby when said rectangular frame is secured in the wall of a furnace, said manifold frame and air supply shell may be uncoupled and removed as a unit by access from the outside of the furnace.

CARL O. NORDENSSON. 

